The present invention relates to a spin finish for elastic fibers. More particularly, it relates to a spin finish for obtaining elastic fibers having excellent anti-tackiness properties and good antistatic properties.
With regard to the spin finish to be attached to elastic fibers in the process of spinning thereof, there have so far been proposed:
{circle around (1)} a method comprising suspending a solid metallic soap as an anti-tackiness agent to thereby produce a mold release effect (Japanese Kokoku Publication Sho-41-286 and Japanese Kokoku Publication Sho-40-5557), a method comprising using a polyether-modified silicone which is a liquid substance at ordinary temperature (Japanese Kokoku Publication Sho-45-40719 and Japanese Kokai Publication Sho-48-19893), and so forth; and
{circle around (2)} a method comprising adding, as an antistatic agent, a phosphate type anionic surfactant such as an alkyl phosphate metal salt (Japanese Kokoku Publication Sho-41-21956).
However, the methods mentioned above under {circle around (1)} have a problem in that even the addition of such an anti-tackiness agent is almost ineffective in reducing the volume resistivity. In the case of suspending a solid metallic soap, in particular, it is a problem that the spin finish is poor in storage stability. As for the method mentioned under {circle around (2)}, the compatibility between the antistatic agent and a base oil is poor and they attach to fibers only poorly; thus the problem is that no satisfactory antistatic effect can be obtained and the anti-tackiness property and antistatic property can never be produced simultaneously.
Accordingly, it is a primary object of the present invention to provide a spin finish for elastic fibers which is excellent in antistatic property and can effectively prevent elastic fibers from tacking with one another in the process of production of elastic fibers.
Another object is to provide a spin finish for elastic fibers which shows good storage stability when a solid metallic soap is suspended therein.
The present inventors made intensive investigations in an attempt to develop the spin finish of the type mentioned above and, as a result, have now completed the present invention.
The invention has five aspects, as mentioned below.
Invention According to the First Aspect
A spin finish for elastic fibers
which comprises an amphoteric surfactant (A1) and/or a cationic surfactant (A2) as well as a base oil (B) and
has a surface tension thereof at 25xc2x0 C. of 14 to 35 mN/m and a volume resistivity thereof at 20xc2x0 C. of 1xc3x97107 to 1xc3x971013 xcexa9xc2x7cm.
Invention According to the Second Aspect
A spin finish for elastic fibers
which comprises an ionic surfactant (A) and a base oil (B) and has a surface tension (S) thereof at 25xc2x0 C. of 14 to 22.5 mN/m and a volume resistivity (xcfx81) thereof at 20xc2x0 C. of 1xc3x97107 to 1xc3x971013 xcexa9xc2x7cm,
xcfx81 and S satisfying the following relation [1]:
xcfx81xe2x89xa61xc3x9710(xe2x88x922.4S+61)xe2x80x83xe2x80x83[1]
Invention According to the Third Aspect
A spin finish for elastic fibers
which comprises a quaternary ammonium salt (A2-11) represented by the following general formula (6), a base oil (B) and a higher fatty acid (C5-30) metal salt powder (C): 
in the formula, R11, R12 and R13 each independently is a group selected from among an alkyl, alkenyl, hydroxyalkyl and polyoxyalkylene group containing 1 to 30 carbon atoms and groups represented by the formula R5xe2x80x94Txe2x80x94R6xe2x80x94 (R5 represents the residue of a C1-30 fatty acid after removal of the COOH group therefrom, R6 represents an alkylene or hydroxyalkylene group containing 1 to 4 carbon atoms and T represents xe2x80x94COOxe2x80x94 or xe2x80x94CONHxe2x80x94); R14 is an alkyl, alkenyl, hydroxyalkyl or polyoxyalkylene group containing 1 to 30 carbon atoms; any two of R12, R13 and R14, together with N, may combinedly form a heterocyclic ring; and Q1xe2x88x92 is an organic acid anion derived from an organic acid-modified silicone.
Invention According to the Fourth Aspect
A method of treating an elastic fiber
which comprises providing an elastic fiber with any of the spin finish mentioned above in an amount of 0.1 to 12% by weight of said fiber.
Invention According to the Fifth Aspect
An elastic fiber
which is obtainable by the above treatment method.
The surface tension (S: mN/m) of the spin finish at 25xc2x0 C. and the volume resistivity (xcfx81: xcexa9xc2x7cm) of the spin finish at 20xc2x0 C. are measured by the following methods.
Method of Measuring the Surface Tension of the Spin Finish at 25xc2x0 C.
A 25-g of the spin finish sample conditioned at 25xc2x0 C.xc2x11xc2x0 C. is weighed in a glass dish having an inside diameter of 80 mm and a depth of 15 mm and subjected to measurement on an automatic surface tensiometer (product of Kyowa Kaimen Kagaku; Wilhelmie method).
Method of Measuring the Volume Resistivity of the Spin Finish at 20xc2x0 C.
The spin finish sample conditioned at 20xc2x0 C.xc2x11xc2x0 C. is subjected to volume resistivity testing as described in the methods of testing of electrical insulation oils (JIS C 2101, para. 24, 1993) (the measurement temperature is 20xc2x0 C.xc2x11xc2x0 C.).
In the following, the invention is described in detail.